Storage system

ABSTRACT

A disk array includes a drive management unit, which is a program for identifying kinds of disk devices and managing different disk devices separately, and a drive management table for storing information to be utilized by the drive management unit. The disk array further includes a program for managing accumulated time of disk devices. The program includes a drive lifetime setting portion for setting lifetimes of drives, a drive start/stop portion for intentionally starting/stopping ATA disk devices, and an operation time measurement portion for measuring accumulated operation time. Since it is necessary to be conscious of difference in reliability and performance among disk devices when forming a RAID, a drive kind notification unit, which is a program for notifying of the kind of a disk device when forming the RAID, is provided.

The present application is a continuation of application Ser. No.10/419,096, filed Apr. 21, 2003, the contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates mainly to a control method for storagesystem and a storage system.

DESCRIPTION OF RELATED ART

As a kind of a storage system connected to a computer, there are diskarrays. Disk arrays are called RAID (Redundant Arrays of InexpensiveDisks). The disk array is a storage system including a plurality of diskdevices arranged in an array form and a control unit for controllingthem. In the disk array, read requests (data readout requests) and writerequests (data write requests) are processed at high speed by paralleloperation of disk devices, and redundancy is added to data. The diskarrays are classified into five levels in accordance with the kind andconfiguration of the added data, as disclosed in “A case for RedundantArrays of Inexpensive Disks (RAID)”, David A. Patterson, Garth Gibson,and Randy H. Katz, Computer Science Division Department of ElectricalEngineering and Computer Sciences, University of California Berkeley. Bythe way, disk devices are storages having a hard disk, an opticalmagnetic disk, or the like.

On the other hand, in disk devices, there are some kinds differing ininterface used for connection to other devices. For example, there aredisk devices (hereafter referred to as FC disk devices) each having afibre channel (hereafter referred to as FC) interface for whichstandardization work is being conducted by ANSI T11, and AdvancedTechnology Attachment disk devices (hereafter referred to as ATA diskdevices) each having an ATA (Advanced Technology Attachment) interfacefor which standardization work is being conducted by ANSI T13.

ATA disk devices are comparatively inexpensive and used in desktopcomputers for homes. On the other hand, FC disk devices are used inbusiness servers of which reliability is required. As compared with theATA disk devices, therefore, the FC disk devices have higher processingperformance in data input/output (hereafter referred to as I/O) and suchhigher reliability that they can withstand continuous operation over 24hours on 365 days. In the case where these disk devices are used instorage systems such as disk arrays, disk devices are used properlysometimes in accordance with the performance, price or the like requiredof the disk array. For example, a technique of improving the reliabilityof data stored in a disk array by using a disk device that is higher inperformance than a data storing disk device as a disk device for storingparities, which are redundant data, is disclosed in JP-A-10-301720.

SUMMARY OF THE INVENTION

In recent years, there is a demand that a data stored in disk devices inthe hosts should be consolidated into one disk array in order todecrease the cost of data management. If the disk arrays are merelycollected into one disk array physically, however, flexibility isimpaired as compared with the case where a plurality of disk arraysdiffering in kind or performance are used. Therefore, there areincreased demands that a more flexible array construction should beconducted while holding down the price of the disk array, by providingdisk devices having high price, high reliability, and high performanceand disk devices having low price and low reliability mixedly in onedisk array and properly using the disk devices according to use.

In the conventional technique, however, it is difficult to unitarilymanage the reliability of disk devices. Therefore, it has not beenconsidered to provide mixedly disk devices differing in reliability ofdisk device itself, such as, for example, device lifetime, and constructand manage a storage system, such as a disk array.

Therefore, the present invention provides a storage system including aplurality of storages differing in reliability of storage itself, and acontrol unit connected to the storages. The control unit furtherincludes an interface to which the storages are connected, and thecontrol unit detects information concerning the reliability of each ofthe storages and manages the detected information. To be concrete, it isconceivable that the control unit detects a kind of each of the storagesand thereby determines a lifetime (predetermined available time given bythe storage type) of the storage. Furthermore, it is also conceivablethat the control unit manages the detected lifetime of each of thestorages and time when the storage has been used, and thereby manages aremaining available time (remaining lifetime) of the disk device.

Furthermore, the control unit in the storage system according to thepresent invention alters a use form of each of the storages according toits remaining lifetime. For example, if the remaining lifetime of amanaged storage has become shorter than a certain predetermined time,then the storage is used for obtaining backup of data, or the use of thestorage is stopped and replaced.

Furthermore, the control unit in the storage system according to thepresent invention previously determines use of each of the storagesaccording to its available time. For example, storages each having along available time are discriminated from storages each having a shortavailable time. A group of storages each having a long available timeare designated as usually used storages, whereas a group of storageseach having a short available time are designated as storages forstoring backup data.

Furthermore, the control unit in the storage system according to thepresent invention controls these storages on the basis of detected kindsof the storages. For example, the control unit issues a command peculiarto a storage according to the detected kind of the storage.

Furthermore, the control unit in the storage system according to thepresent invention may have a program for identifying kinds of storagesand managing different storages separately, and a drive management tablethat stores management information.

Furthermore, the storage system according to the present invention, forexample, sets a lifetime of each of the drives, intentionallystart/stops each of ATA disk devices, and measures accumulated operationtime.

Furthermore, a storage management server for managing an environmentincluding a mixture of storage systems described above may also beprovided.

Furthermore, the storage system conducts data duplication betweenstorage systems or within the storage system, and assigns logicalstorage regions that become subjects of data duplication on the basis oflifetime management.

By the way, both logical storages and physical storages, such as diskdevices, are included in “storages.”

Other objects, features and advantages of the invention will becomeapparent from the following description of the embodiments of theinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system configuration diagram in a first embodiment of theinvention;

FIG. 2 is a diagram of a drive management table in the first embodiment;

FIG. 3 is a configuration diagram of an input unit in the firstembodiment;

FIG. 4 is a configuration diagram of an output unit in the firstembodiment;

FIG. 5 is a diagram showing an example of an LU management table in thefirst embodiment;

FIG. 6 is a flow chart of a drive lifetime management operation in thefirst embodiment;

FIG. 7 is a system configuration diagram in a second embodiment of theinvention;

FIG. 8 is a diagram of a port bypass circuit in the second embodiment;

FIG. 9 is a diagram of an FC-ATA conversion I/F in the secondembodiment;

FIG. 10 is a system configuration diagram in the third embodiment of theinvention;

FIG. 11 is a diagram showing an example of an LU pair management tablein the third embodiment;

FIG. 12 is a diagram of a storage management server in the thirdembodiment;

FIG. 13 is a diagram showing an example of a device list in the thirdembodiment;

FIG. 14 is a diagram showing an example of an LU evaluation item tablein the third embodiment;

FIG. 15 is a flow chart of logical unit (LU) assignment processing inthe third embodiment;

FIG. 16 is a flow chart of host LU assignment processing in the thirdembodiment;

FIG. 17 is a flow chart of copy destination LU assignment processing inthe third embodiment;

FIG. 18 is a flow chart of assignment candidate LU search processing inthe third embodiment;

FIG. 19 is a diagram showing an example of an LU remaining lifetimewatermark table in the third embodiment; and

FIG. 20 is a flow chart of LU lifetime management processing in thethird embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a diagram showing a first embodiment of a storage systemaccording to the present invention. A disk array 700, which is anexample of a storage system, is connected to a computer (hereafterreferred to as host) 100 and a management terminal 500. As for aninterface used for connection to the host 100, an FC or a SCSI isconceivable. The disk array 700 includes a disk array control unit 200,an FC disk group 310, and an ATA disk group 410.

The FC disk group 310 includes a plurality of FC disk devices 301. TheATA disk group 410 includes a plurality of ATA disk devices 401. In thepresent embodiment, FC disk devices and ATA disk devices areexemplified. In application of the present invention, however, diskdevices used in the disk array are not limited to these disk devices.

The management terminal 500 includes an input unit 510, such as akeyboard device, used by the user when inputting setting concerning thedisk array 700, and an output unit 520, such as a display device, forshowing information concerning the disk array 700 to the user.

The disk array control unit 200 includes a CPU 201 for executing aprogram to control the disk array 700, a memory 202, a cache 203 fortemporarily storing input and output data of the host 100, a host FC I/F204 for controlling data transmission and reception between the host 100and the disk array control unit 200, a drive FC I/F 205 for controllingdata transmission and reception between the FC disk group 310 and thedisk array control unit 200, a drive ATA I/F 206 for controlling datatransmission and reception between the ATA disk group 410 and the diskarray control unit 200, and a management interface (I/F) 207 forcontrolling information transmission and reception between themanagement terminal 500 and the disk array control unit 200. Thesecomponents are connected to each other via an internal bus.

The drive FC I/F 205 is connected to the FC disk group 310 via an FC. Inthe present embodiment, the fibre channel arbitration loop is used as aprotocol for the FC. However, the protocol is not limited to this, butanother protocol, such as the point-to-point or fabric of the FC, alsomay be used.

The drive ATA I/F 206 is connected to ATA disk devices included in theATA disk group 410 via an ATA bus.

Various programs to be executed by the CPU 201 to control the disk array700 are stored in the memory 202. To be concrete, a RAID control program210 for controlling the operation of the disk array 700, and amanagement agent 800 for managing the configuration of the disk array700 are stored in the memory 202. Various kinds of information is alsostored in the memory 202. To be concrete, a drive management table 240for recording information concerning the FC disk group 310 and the ATAdisk group 410, and an LU management table 245 for recording informationconcerning a logical storage region (hereafter referred to as FCLU) 320created in the FC disk group 310 and a logical storage region (hereafterreferred to as ATA LU) 420 created in the ATA disk group 410 are alsostored in the memory 202.

The RAID control program 210 is formed of several subprograms. To beconcrete, the RAID control program 210 includes a drive command issuanceprogram 220 to be executed by the CPU 201 when issuing a command to theFC disk group 310 or the ATA disk group 410, a drive management program230 to be executed to manage the FC disk group 310 and the ATA diskgroup 410, and an LU management program 225 to be executed to managelogical storage regions (hereafter referred to as LU) preset inrespective disk groups.

The management agent 800 is formed of several subprograms. To beconcrete, the management agent 800 includes a drive information settingprogram 250 to be executed when setting information (hereafter referredto as drive information) concerning a disk device in response to aninput from the management terminal 500, a drive information notificationprogram 260 to be executed when outputting drive information to themanagement terminal 500, an array information setting program 270 to beexecuted when setting information (hereafter referred to as arrayinformation) concerning the disk array 700, and an array informationnotification program 280 to be executed when outputting arrayinformation to the management terminal 500.

FIG. 2 is a diagram showing an example of contents of the drivemanagement table 240. The drive management table 240 has items forregistering various kinds of information for each of disk devicesincluded in the disk array 700. To be concrete, the drive managementtable 240 has a “drive No.” column 240 a for registering a numberassigned to the disk device, a “drive type” column 240 b for registeringa type of the disk device, an “array configuration” column 240 c forregistering an RAID group (a set of disk devices forming redundancy)including the disk device and its RAID level (hereafter referred to asarray configuration), a “use” column 240 d for registering a user's use(hereafter referred to as array use) of a RAID group including the diskdevice, a “start situation” column 240e for registering a situation asto whether the disk device is started or stopped, an “accumulated time”column 240 f for registering accumulated operation time of the diskdevice, a “lifetime setting” column 240 g for registering lifetime ofthe disk device, a “remaining lifetime” column 240 h for registering aremaining lifetime of the disk device, and an “automatic migrationspecification” column 240 i for registering whether data should beautomatically migrated (hereafter referred to as automatic migration) toanother disk device when the disk device is judged to have arrived atthe lifetime.

To be concrete, information indicating FC or ATA is registered in the“drive kind” column 240 b. A number indicating an order in which theRAID group has been created, and information indicating the RAID levelare registered in the “array configuration” column 240 c. For example, adisk device for which “(1)RAID5” has been registered is a disk deviceincluded in a RAID group having a RAID level 5 created first. In thedisk array 700, a plurality of RAID groups can be created. For example,RAID groups RAID1 and RAID5 can be created. Disk devices included in theRAID group may be all devices included in the disk array 700 or may be apart of them.

In the “use” column 240 d, to be concrete, information, such as DBindicating the use of the database and FS indicating the use of the filesystem, is registered. In the “start situation” column 240 e,information indicating ON is registered in the case where the diskdevice is started, and information indicating OFF is registered in thecase where the disk device is stopped. In the “remaining lifetime”column 240 h, a value indicating a difference between time registered inthe “lifetime setting” column 240 g and time registered in the“accumulated time” column 240 f is stored. In the “automatic migrationspecification” column 240 i, 1 is registered when setting automaticmigration of data stored in the disk device, and 0 is registered whennot setting automatic migration of data stored in the disk device.

The drive management program 230 is executed in the CPU 201, when thedisk array control unit 200 discriminates the kind of the disk device,when the disk array control unit 200 measures the operation time of thedisk device, when the disk array control unit 200 controls the start andstop of the disk device, and when the disk array control unit 200executes the automatic migration in response to arrival of the diskdevice at the lifetime.

The drive information setting program 250 is executed in the CPU 201,when the disk array control unit 200 sets the kind of the disk device inthe drive management table 240 in accordance with an input from themanagement terminal 500, when the disk array control unit 200 sets thelifetime of the disk device in the drive management table 240, and whenthe disk array control unit 200 sets the situation of start and stop ofthe disk device in the drive management table 240.

The drive information notification program 260 is executed in the CPU201, when the disk array control unit 200 notifies the managementterminal 500 of the kind of the disk device, when the disk array controlunit 200 notifies the management terminal 500 of the accumulatedoperation time of the disk device, when the disk array control unit 200notifies the management terminal 500 of the situation of start and stopof the disk device, when the disk array control unit 200 orders exchangeof the disk device, and when the disk array control unit 200 notifiesthat automatic migration of data to another disk device has beenconducted because of arrival of the disk device at the lifetime.

The array information setting program 270 is executed in the CPU 201,when the disk array control unit 200 sets the array configuration inaccordance with an input from the management terminal 500, and when thedisk array control unit 200 sets the use of the array in accordance withan input from the management terminal 500.

The array information notification program 280 is executed in the CPU201, when the disk array control unit 200 notifies the managementterminal 500 of information concerning the array configuration, and whenthe disk array control unit 200 notifies the management terminal 500 ofinformation concerning the use of the array.

FIG. 3 is a diagram showing an example of a picture displayed on theoutput unit 520 of the management terminal 500 when the user or managerof the disk array 700 conducts setting of the disk array 700. In thiscase, the following regions are displayed on the output unit 520. Theregions are a drive kind setting region 551 for displaying an input kindof the disk device, a drive lifetime setting region 552 for displayingan input lifetime of the disk device, a drive start/stop setting region553 for displaying a start/stop condition of the disk device specifiedby the user, an array configuration setting region 571 for displaying aninput array configuration, and an array use setting region 572 fordisplaying an input array use. While watching the picture, the userinputs necessary data via the input unit, and ascertains contents of theinput data.

FIG. 4 shows an example of a picture displayed on the output unit 520when the user or manager of the disk array 700 acquires information ofthe disk array 700 via the management terminal 500. In this case, thefollowing regions are displayed on the output unit 520.

The regions are a drive kind display region 561 for displaying a kind ofa disk device included in the disk array 700, an operation time displayregion 562 for displaying accumulated operation time of a disk deviceincluded in the disk array 700, a drive state display region 563 fordisplaying a start/stop situation of the disk device, an exchange orderdisplay region 564 for displaying an exchange order of the disk device,an automatic migration notification display region 565 for displayingthat automatic migration of data to another disk device has beenconducted because of arrival of some disk device at the lifetime, anarray configuration display region 581 for displaying a preset arrayconfiguration, and an array use display region 582 for displaying apreset array use. By displaying this picture on the management terminal500, the manager or user can ascertain the state of the disk array 700.

FIG. 5 is a diagram showing an example of contents of the LU managementtable 245 used by the disk array control unit 200 to manage the FCLU 320and the ATA LU 420. In the LU management table 245, the following itemsfor registering information is provided for each LU in order that thedisk array control unit 200 may manage respective LUs.

In “LU No.” column 245 a, identifiers arbitrarily assigned to respectiveLUs are registered. In “host assignment situation” column 245 b,information of “presence” or “absence” indicating whether an LU has beenassigned to the host 100 is registered (hereafter referred to as used ifassigned, and referred to as unused if not assigned). In “SCSI ID”column 245 c, a SCSI ID number, which is assigned to a logical storageincluding an LU, is registered if the LU is assigned to the host 100. In“LUN” column 245 d, a SCSI logical unit number required for the host 100to access an LU is registered if the LU is assigned to the host 100.

In “capacity” column 245 e, a storage capacity assigned to an LU isregistered. In “LU kind” column 245 f, information indicating the kindas to whether the LU is the FCLU 320 or the ATA LU 420 is registered. In“LU remaining lifetime” column 245 g, remaining lifetime of the LU isregistered. To be concrete, the disk array control unit 200 acquiresremaining lifetime values of respective disk devices forming the LUregistered in a “drive No. list” column 245 h, from the drive managementtable 240, and registers a minimum value among them.

In the “drive No. list” column 245 h, information that indicates diskdevices forming the LU is registered as a list of drive Nos. In“evaluation value” column 245 i, information indicating an evaluationvalue, which serves as a criterion of LU selection, is registered. Amethod for calculating the evaluation value will be described later. Inthe case of a used LU, a maximum value (+99999 in the example of FIG. 5)which can be registered is registered in “evaluation value” column 245i.

Hereafter, the case where the disk array control unit 200 conductsconstruction of the drive management table 240, the LU management table245, and the RAID group in accordance with an order from the user ormanager will be described.

When a power supply of the disk array 700 is turned on, the disk arraycontrol unit 200 executes the drive management program 230, and makesinquiries about disk devices connected to the drive FC I/F 205 and thedrive ATA I/F 206. As an example of inquiries about the disk devices,there is an example in which a ModeSelect command is used. To beconcrete, the disk array control unit 200 issues the ModeSelect commandto respective disk devices. Upon receiving the ModeSelect command, thedisk device transmits page information stored in the disk device to thedisk array control unit 200. Page information contains informationconcerning the kind of the disk device. The disk array control unit 200discriminates the kind of the inquired disk device on the basis of pageinformation acquired from the disk device.

Furthermore, the disk array control unit 200 executes the driveinformation setting program 250, and registers pertinent information inthe “drive No.” and the “drive kind” items of the drive management table240 with respect to all of the detected disk devices.

The kind of the disk device may be input by the user via the input unitof the management terminal 500. In this case, the disk array controlunit 200 registers information in the drive management table 240 on thebasis of information received from the management terminal 500.

After detection or registration of the kind of the disk device has beenconducted, the disk array control unit 200 sets the array configurationand array use on the basis of an order from the user.

First, upon receiving an acquisition order of information of “drive No.”and “drive kind” input by the user via the input unit 510 in themanagement terminal 500, the disk array control unit 200 executes thedrive information notification program 260, acquires requestedinformation from the drive management table 240, and transfers therequested information to the management terminal 500 via the managementI/F 207. The management terminal 500 displays received information in aportion for displaying the “drive No.” and “drive kind” in the drivekind display region 561, which is displayed on the output unit 520. Inthe case where the user defines the kind of the disk device, the presentprocessing may be omitted.

Thereafter, the user selects an arbitrary disk device on the basis ofinformation displayed in the drive kind display region 561, which isdisplayed on the output unit 520 of the management terminal 500, andinputs an order for constructing a RAID group by using the selected diskdevice, from the input unit 510 by using the array configuration settingregion 571. Furthermore, the user inputs the use of the RAID group to beconstructed. The disk array control unit 200 executes the arrayinformation setting program, and registers array information, such asthe RAID group and use, received via the management I/F 207 in the“array configuration” and “use” columns of the drive management table240.

The user constructs a RAID group on the basis of the kind of the diskdevice displayed in the drive kind display picture 561. At this time,however, it is possible to prevent an ATA disk device, which is low inreliability and performance, from being set for array use, which isrequired to be high in reliability and performance, such as array usefor a database. To be concrete, in the case where “use” is specified bythe user, a decision is made as to whether the lifetime of the diskdevice meets the use, on the basis of information concerning thelifetime of the disk device described later. And warning is given to theuser in accordance with a result of the decision.

For example, in the case where it is attempted to set an ATA disk devicefor array use, which is high in reliability and performance, themanagement terminal 500 may issue caution or warning to the user via theoutput unit 520. Furthermore, when displaying disk devices in the drivekind display picture 561, disk devices differing in kind may havedifferent patterns so as to be able to be discriminated from each other.

It is also possible to consider a method of disregarding the lifetime ofthe disk device when first creating a RAID group and adding theremaining lifetime of the disk device as a decision criterion for newuse setting when remaking a RAID group again.

Upon receiving information for ordering information acquisition of“array configuration” and “use” input by the user via the input unit 510of the management terminal 500, the disk array control unit 200retrieves information requested from the management terminal 500 via themanagement I/F 207, from the drive management table 240 and transfersthe retrieved information, by executing the array informationnotification program. Upon receiving the information, the managementterminal 500 displays the acquired information in the arrayconfiguration display region 581 and the array use display region 582 ofthe output unit 520.

Lifetime management of the disk device conducted by the disk arraycontrol unit 200 will now be described. As described earlier, the diskarray control unit 200 controls the management of the accumulatedoperation time and planned start/stop of disk devices, and automaticmigration of data.

The “lifetime” of a disk device refers to time preset by a manufacturerof the disk device on the basis of specifications, such as the mean timebetween failures and recommended service time, of the disk device, ortime preset by the disk array manager on the basis of time preset by amanufacturer of the disk device. The “lifetime” of a disk device isdefined as “time serving as a criterion of preventive maintenance forpreventing a failure caused by a long time operation of the diskdevice.” For a disk device that has exceeded the “lifetime,” therefore,it is necessary to execute migration of stored data and the maintenancepersonnel must execute exchange to a new disk device.

For conducting the lifetime management, first, the disk array 700conducts lifetime setting and automatic migration specification for eachdisk device. The present processing may be conducted together when thedisk array control unit 200 conducts setting of various tables accordingto a user's order, or the present processing may be conducted before thedisk array control unit 200 conducts setting of various tables accordingto a user's order. The lifetime setting and automatic migrationspecification for each disk device are conducted as described below.

Upon receiving the order for acquiring information of “drive No.” and“drive kind” input from the input unit 510 of the management terminal500 by the user, the disk array control unit 200 transfers the requestedinformation to the management terminal 500 via the management I/F 207.Upon receiving the information, the management terminal 500 displays thereceived information concerning “drive No.” and “drive kind” in thedrive kind display region 561 of the output unit 520.

The user discriminates the kind of the disk device on the basis of theinformation displayed in the drive kind display region 561, and conductssetting as to the lifetime of the disk device and as to whetherautomatic migration is necessary via the input unit 510 of themanagement terminal 500. Upon receiving information concerning thelifetime of the disk device and whether automatic migration in the diskdevice is necessary via the management I/F 207, the disk array controlunit 200 executes the drive information setting program 252, andregisters the received information in “lifetime setting” and “automaticmigration specification” columns of the drive management table 240. Theinformation of “lifetime setting” and “automatic migrationspecification” may not be specified by the user, but the disk arraycontrol unit 200 may determine the information of “lifetime setting” and“automatic migration specification” uniquely on the basis of the kind ofthe disk device and set the information in the drive management table240. For example, in the case of an FC disk device, it is considerableto predict from the beginning that the lifetime is long and set theinformation in the drive management table 240.

FIG. 6 is a flow chart showing a procedure of the drive lifetimemanagement conducted by the disk array control unit 200.

First, the disk array control unit 200 starts measurement of theoperation time of respective disk devices included in the disk array 700and accumulates results of the measurement in the “accumulated time” ofthe drive management table 240, by executing the drive managementprogram 230. When measuring the operation time, the disk array controlunit 200 measures the operation time on the basis of a clock included inthe disk array 700 (step 1003). Thereafter, the disk array control unit200 compares values in the “accumulated time” and “lifetime setting” inthe drive management table 240, and determines whether the accumulatedtime has reached the preset lifetime. Timing for the comparison may bearbitrary timing that is asynchronous with other processing (step 1004).

If the accumulated time has not reached the lifetime, then theprocessing returns to the step 1003. If the accumulated time has reachedthe preset life-time, then the disk array control unit 200 determineswhether there is 1 registered in the “automatic migration specification”column 240 i for the disk device (step 1005). If the automatic migrationis not specified (i.e., the registered value is 0), then the disk arraycontrol unit 200 executes the drive information notification program260, and thereby notifies the management terminal 500 of a disk devicethat has reached in accumulated time the preset lifetime as a diskdevice to be exchanged, via the management I/F 207.

The management terminal 500 displays the disk device that has reached inaccumulated time the preset lifetime as a disk device to be exchanged,in the exchange order display region 564 of the output unit 520 (step1006). If the automatic migration is specified for the disk device thathas reached in accumulated time the preset lifetime (i.e., theregistered value is 1), then the disk array control unit 200 executesthe drive management program 230 and the RAID control program 210, andthereby transfers data stored in the disk device that has reached inaccumulated time the preset lifetime to a disk device serving as theautomatic migration destination. The disk device that serves as theautomatic migration destination is specified beforehand by the user orthe like. In this case, one disk device may be specified as an automaticmigration destination device for a plurality of disk devices (step1010).

After the data transfer has been completed, the disk array control unit200 notifies the management terminal 500 of information concerning thedisk device designated as the automatic migration destination, via themanagement I/F 270 (step 1011). Upon being notified of the information,the management terminal 500 displays the information concerning the diskdevice designated as the automatic migration destination, in theautomatic migration notification display region 565 on the output unit520. The drive management program 230 clears the “accumulated time” inthe drive management table 240 concerning the drive subjected to theautomatic migration (step 1012), and the processing returns to the step1003.

In the present embodiment, automatic migration is conducted with respectto a disk device that has reached in accumulated time the lifetime.However, automatic migration may be conducted with respect to a diskdevice that is less in remaining lifetime than a certain threshold. Inthis case, the disk array control unit 200 ascertains values registeredin the “remaining lifetime” 240 h, and discriminates a disk device thatis less in remaining lifetime than the threshold.

On the other hand, the disk array control unit 200 controls thestart/stop of the operation of the disk devices in order to prevent anincrease in the accumulated operation time of the disk devices. Thiscontrol is conducted independently from the lifetime management shown inFIG. 6.

The disk array control unit 200 conducts start/stop of a disk device onthe basis of a preset trigger. The trigger for starting/stopping a diskdevice may be, for example, time when user's access is completelystopped, such as nighttime. Or the fact that the remaining lifetime ofsome disk device has become shorter than a certain threshold may be usedas a trigger of start/stop of the disk device.

Or the user may directly specify the start/ stop of the disk device viathe input unit 510 of the management terminal 500. The managementterminal 500 transmits an order concerning the start/stop of the diskdevice to the disk array control unit 200 via the management I/F 207.The disk array control unit 200 controls the start/stop of the diskdevice on the basis of the received order. Thereafter, the disk arraycontrol unit 200 registers the start/stop situation of the disk devicein the “start situation” in the drive management table 240. Star/stop ofa drive is conducted by issuing a Start/StopUnit command to the drive.

When acquiring the start situation and accumulated operation time of adrive, the user issues an order at the input unit 510 in the managementterminal 500 to acquire information of the “start situation” and“accumulated time.” The disk array control unit 200 transfers thespecified information to the management terminal 500 via the managementI/F 207. The management terminal 500 displays the received startsituation of the disk device and the accumulated operation time of thedisk device in the drive state display region 563 and the operation timedisplay region 562 of the output unit 520.

The user may execute disk device exchange beforehand on the basis of thedisplayed accumulated operation time or remaining lifetime of the drive.

The case where the disk array control unit 200 issues a command to adisk device having a different interface will now be described.

For example, the ATA disk device 401 cannot conduct processing on acommand having a plurality of tags. Upon receiving a command that ordersto write data from the host 100, therefore, the disk array control unit200 executes the drive command issuance program 220 and determines acommand to be issued to a disk device. To be concrete, when issuing acommand to the disk device, the disk array control unit 200 refers tothe “drive kind” in the drive management table 230, and determineswhether issuance destination of the command is an FC disk device 301 oran ATA disk device 401. In the case of an ATA disk device 401, the diskarray control unit 200 does not issue a command having a plurality oftags, but issues a single command.

According to the present embodiment, it becomes possible to provide diskdevices differing in reliability, such as in lifetime, mixedly andmanage the disk devices in the same disk array 700. Furthermore, it ispossible to determine the use of LUs by considering the reliability ofdisk devices that form a RAID group. Furthermore, it becomes possible toprovide disk devices differing in control scheme mixedly and manage thedisk devices in the same disk array.

FIG. 7 is a diagram showing a second embodiment of a computer systemaccording to the present invention. Hereafter, only differences from thefirst embodiment will be described. In FIG. 7, a disk array 700′includes an FC drive chassis 300 for storing an FC disk group 310, andan ATA drive chassis 400 for storing an ATA disk drive group 410. FCdisk devices 301 stored in the FC drive chassis 300 are connected to adrive FC I/F 205 and the ATA drive chassis 400 via a port bypass circuit330 included in the FC drive chassis 300. Furthermore, the FC drivechassis 300 and the ATA drive chassis 400 are connected to each other byan FC loop 600, to be concrete, a fibre cable.

ATA disk devices 401 stored in the ATA drive chassis 400 cannot beconnected directly to the FC loop 600. Therefore, the ATA drive chassis400 includes an FC-ATA conversion I/F 430 for converting conversionbetween the FC interface and the ATA interface. Therefore, the ATA diskdevices 401 are connected to the drive chassis 300 via the I/F 430 andthe FC loop 600.

FIG. 8 is a diagram showing a configuration of the port bypass circuit330. The port bypass circuit 330 shown in FIG. 8 includes five ports.Furthermore, the port bypass circuit includes as many selectors 331 asports, and thereby executes loop wiring for each port. The selector 331forms a signal path through a port when wiring is connected to the port,and forms a signal path through an internal circuit, which does notthrough a port, when the port is not connected.

FIG. 9 is a diagram showing a configuration of the FC-ATA conversion I/F430. The FC-ATA conversion I/F 430 functions to connect ATA disk devicesto the FC I/F. The FC-ATA conversion I/F 430 includes an FC I/F 431serving as an interface to the FC, an ATA I/F 438 serving as aninterface to the ATA, a memory 441, a CPU 440 for executing programsstored in the memory 441, and an internal bus 442 for connecting the FCI/F 431, the ATA I/F 438, the memory 441 and the CPU 440.

In the memory 441, an FC command reception program 432 to be executedwhen receiving a command from the FC, an FC data transfer program 433 tobe executed when transmitting/receiving data to/from the FC, a commandconversion program 434 to be executed when converting an FC command to acommand for the ATA, a data buffer 435 for conducting data bufferingbetween the FC and ATA, an ATA command issuance program 436 to beexecuted when issuing a command obtained by the conversion to the ATAside, an ATA data transfer program 437 to be executed whentransmitting/receiving data to/from the ATA, and a command buffer 439for conducting temporary buffering to hold and regenerate a command.

The CPU 440 executes the FC command reception program 432 to receive acommand from the FC, and executes the FC data transfer program 433 toconduct data transfer between the FC I/F 431 and the data buffer 435.Furthermore, the CPU 440 executes the command conversion program 434 toconvert an FC command to a command for the ATA, and executes the ATAcommand issuance program 436 to issue a command obtained by theconversion to the ATA side. Furthermore, the CPU 220 executes the ATAdata transfer program 437 to conduct data transfer between the ATA I/F438 and the data buffer 435.

In the present embodiment, it is possible to connect the disk arraycontrol unit 200′ to the ATA disk devices 401 via the FC by using theFC-ATA conversion I/F 430. The FC-ATA conversion I/F 430 converts acommand received from the disk array control unit 200′ to a command forATA disk device. Furthermore, data transmitted and received between thedisk array control unit 200′ and an ATA disk device are also convertedby the FC-ATA conversion I/F 430.

According to the present embodiment, it is possible to connect an ATAdisk device to a fibre channel arbitrated loop, which is an interfacefor connecting an FC disk device.

FIG. 10 is a diagram showing a third embodiment of a computer systemaccording to the present invention. Hereafter, differences from thefirst embodiment will be described. In addition to the configuration ofthe first embodiment, the computer system of the present embodimentincludes another disk array 701 B connected to a disk array 701A, a hostcomputer 100 connected to the disk array 701B, and a storage managementserver 10000, which is a computer connected to the disk arrays 701A and701B via a management network 20000. The two disk arrays are connectedto each other via a host FC I/F 204 included in each disk array and aremote copy connection 30000. As for a method for the remote copyconnection 30000, for example, a fibre channel, an ESCON, or the likecan be considered. In the present embodiment, however, a distinction isnot especially made among them. Furthermore, for connection between eachdisk array 701 and the management network 20000, a management I/F 207included in each disk array 701 is used.

In addition to the configuration of the first embodiment, the disk array701 in the present embodiment newly includes an LU pair management table246 in a memory 202 in a disk array control unit 2001. Furthermore, in aRAID control program, a program module for controlling duplication(hereafter referred to as remote copy) of data between the disk array701A and the disk array 701B connected thereto, and a program module formanaging duplication (hereafter referred to as intra-device replication)of data in the disk array 701A or 701B are newly added. As for methodsfor implementing the remote copy, there are variations, such assynchronous operation (in which data write request completion is notreported to a host computer until data duplication is completed) andasynchronous operation (in which data write request completion isreported to a host computer without waiting for the data duplicationcompletion). In the present embodiment, however, a distinction is notespecially made among them.

FIG. 11 is a diagram showing an example of the LU pair management table246. By using the LU pair management tables 246 registered in respectivememories 202, the disk arrays 701A and 701B manage a pair of LUs(hereafter referred to as LU pair) that hold the same data between diskarrays used for remote copy, or a pair of LUs that hold the same data inthe disk array 701 generated by the intra-device replication.

The LU pair management table 246 has items of “LU pair No.”, “copysource LU information”, “copy destination LU information”, and “pairstate”.

In an “LU pair No.” column 246 a, an identifier assigned arbitrarily toan LU pair is registered. In the present embodiment, identifiers areassigned without discriminating LU pairs between the disk arrays 701from LU pairs in the disk array 701.

The “copy source LU information” item has three sub-items describedbelow. In an “LU pair No.” column 246 b, an LU No. assigned to an LU(hereafter referred to as copy source LU) that stores original dataincluded in an LU pair provided with some identifier is registered. In a“pair attribute” column 246 c, information for determining whether theLU pair is an LU pair based on the remote copy or an LU pair based onthe intra-device replication, to be concrete, a value indicating“remote” in the case of the remote copy or a value indicating “local” inthe case of the intra-device replication is registered. In a “LU kind”column 246 d, a kind of a disk device that stores the copy source LU isregistered.

The “copy destination LU information” item has three sub-items describedbelow. In a “device ID” column 246 e, an identifier assigned to a diskarray 701 to which an LU (hereafter referred to as copy destination LU)paired with the copy source LU belongs is registered. For example, inthe case of the remote copy, an identifier assigned to a disk array 701of the remote copy destination is registered. In the case of anintra-device replication, an identifier assigned to a disk array 701having a copy source LU is registered. In an “LU pair No.” column 246 f,an LU No. assigned to a copy destination LU is registered. In a “LUkind” column 246 g, a kind of a disk device that holds the copydestination LU is registered.

In a “pair state” column 246 h, the current state of the LU pair isregistered. For example, a value indicating whether the current state isa state (hereafter referred to as pair state) in which synchronizationof data stored in respective LUs of the LU pair is attained and contentsof data stored in the respective LUs coincide with each other, or astate (hereafter referred to as split state) in which synchronization ofdata is not attained between the LUs of the LU pair is registered.

The disk array 701 conducts the following operations by using thefunction of the intra-device replication. For example, the disk array701 changes an LU pair that assumes the pair state to the split state atarbitrary time. By doing so, data held by the LU pair at arbitrary timeis preserved in the copy destination LU (such processing is referred toas snapshotting). Thereafter, the host 100 reads out data from the copydestination LU, and writes the data into another storage, such as a tapedevice. As a result, it is possible to obtain a backup of data stored inthe LU pair at time of snapshot acquisition. Furthermore, the copydestination LU itself after the snapshot has been acquired may bepreserved as the backup of the data.

It is also possible to combine an LU pair of the remote copy with an LUpair of the intra-device replication. For example, in the case whereremote copy is conducted between the disk arrays 701A and 701B, the copydestination LU held by the disk array 701 B is used as the copy sourceLU of the intra-device application to be executed by the disk array 701B. And within the disk array 701 B, the copy destination LU that servesas an LU pair for the intra-device application may be created. The copydestination LU thus created can be used for data backup by attaining thesplit state as described above.

The user can freely combine the FCLU 320 and the ATA-LU 420, and set thecopy source LU and the copy destination LU (hereafter referred to as LUpair). Especially, the user can set the assignment of the LU pair withdue regard to features of respective LUs via the storage managementserver 10000 described later. For example, it is possible to set the LUkind to the feature, and assign the fibre channel LU 320 using a FC diskdevice of high performance and high reliability to the copy source LUand assign the ATA-LU 420 using an ATA disk device of low price to thecopy destination LU. Furthermore, it is possible to set the LU remainingtime to the feature, and conduct setting so as not to select an LUhaving a disk device that is short in remaining lifetime as a subject ofassignment, or use the LU having a disk device that is short inremaining lifetime, only for the copy destination of the intra-devicereplication.

The storage management server 10000 will now be described. FIG. 12 is adiagram showing a configuration of the storage management server 10000.

The storage management server 10000 includes a CPU 11000, a main memory12000, a storage unit 13000, a management I/F 14000 for connection to amanagement network 20000, an output unit 15000, and an input unit 16000.These components are connected to each other via a communication line,such as a bus. In the storage unit 13000, a storage manager 13100serving as a program executed by the CPU 11000, a storage repository13200 serving as a region for storing information collected from thedisk array 701, a device list 13300 for holding a list of the disk array700 to be managed by the storage manager 13100, an LU evaluation itemtable 13400, and an LU remaining lifetime watermark table 13500 formanaging the remaining lifetime of the LU.

In the storage repository 13200, information stored in the drivemanagement table 240, the LU management table 245, and the LU pairmanagement table 246, which are included in the disk arrays 701A and701B, is periodically collected, and duplications of these tables arecreated. Furthermore, the device list 13300, the LU evaluation itemtable 13400, and the LU remaining lifetime watermark table 13500 arecreated by execution of the storage manager 13100 conducted by thestorage management server 10000 on the basis of a user's order.

FIG. 13 is a diagram showing an example of the device list 13300. Thedevice list 13300 is used by the storage management server 10000 toascertain the disk array 701 to be managed by the storage managementserver 10000 itself and refer to information required to communicatewith the disk array 701. In a “subject device No.” column 13300 a, anidentifier assigned arbitrarily to the disk array 701, which is managedby the storage management server 10000, is registered. In a “device ID”column 13300 b, a peculiar identifier assigned to the disk array 701 isregistered. In an “IP address” column 13300 c, information required forthe storage management server 10000 to communicate with the disk array701, such as information concerning an IP address assigned to the diskarray 700 in the case where an IP network is used as the managementnetwork 20000, is registered.

FIG. 14 is a diagram showing an example of the LU evaluation item table13400. In the LU evaluation item table 13400, items to be consideredwhen selecting LUs of the LU pair and evaluation contents in the itemsare registered beforehand. When retrieving an LU that meets a user'sorder, the storage management server 1000 evaluates respective LUs withrespect to items registered in the LU evaluation item table 13400, andregisters evaluation contents specified by the table in the item of theevaluation value 245 i in the duplication (hereafter referred to as LUmanagement table 245′) of the LU management table 245. Thereafter, thestorage management server 10000 selects a suitable LU, and exhibits theselected LU to the user.

In an “evaluation item” column 13400 a, evaluation items at the time ofLU specification which can be selected by the user are registered. In an“evaluation subject LU management table column” column 13400 b, an itemin the LU management table 245, such as the LU kind 245 f, which becomesthe evaluation subject in the evaluation item, is registered. In an“input condition reading with expression changed” column 13400 c, it isregistered whether reading a condition input by the user, while changingits expression is needed when evaluating LUs registered in the LUmanagement table 245′. In a “penalty at the time of conditionsatisfaction” column 13400 d, a value to be added to the value of the“evaluation value” column 245 i in the LU management table 245′ when thecondition input by the user agrees with a content registered in an itemof the LU management table 245′ to be evaluated is stored. In a “penaltyat the time of condition unsatisfaction” column 13400 e, a value to beadded to the value of the “evaluation value” column 245 i in the LUmanagement table 245′ when the condition input by the user does notagree with a content registered in the column of the LU management table245′ to be evaluated is registered. A concrete LU evaluation method willbe described later.

FIG. 19 is a diagram showing an example of the LU remaining lifetimewatermark table 13500. The LU remaining lifetime watermark table 13500is used when the storage management server 10000 manages the remaininglifetimes of LUs included in respective disk arrays 701. To be concrete,the LU remaining lifetime watermark table 13500 has the following itemsfor registering information.

In a “watermark No.” column 13500 a, an identifier assigned arbitrarilyto each of a plurality of preset watermarks is registered. In a “deviceID” column 13500 b, an identifier assigned to a disk array 701 to bemanaged in remaining lifetime is registered. In a “monitoring subject LUlist” column 13500 c, information indicating an LU that is included inLUs of the disk array 701 to be managed and that is actually managed inremaining lifetime is registered. In a “remaining lifetime watermark”column 13500 d, information that indicates a watermark corresponding tothe identifier is registered.

In the present embodiment, the storage management server 10000ascertains the remaining lifetime of the LU registered as the managementsubject, and if the ascertained remaining lifetime becomes shorter thana preset watermark, the storage management server 10000 outputs awarning to the user. According to circumstances, the storage managementserver 10000 urges the user to set the LU migration or issues anautomatic migration order to the disk array device. In the case wherethe importance of data stored in the LU is low, the lifetime of diskdevices included in the LU may be used as a decision criterion insteadof using the lifetime as the decision criterion. In this case, however,fast exchange of disk devices becomes necessary.

In the present embodiment, the user can consider parameters concerningperformance and reliability of disk devices, when creating LUs of thedisk array 701 including a mixture of disk devices having differentinput/output I/Fs by using the storage management server 10000.Hereafter, this processing is referred to as LU assignment processing.Unless otherwise stated, processing described hereafter with referenceto a flow chart is processing conducted by execution of the storagemanager 13100 effected by the storage management server 10000.

FIG. 15 is a flow chart showing a procedure of LU assignment processing2000. First, on the basis of an order from the user, the storagemanagement server 10000 determines whether processing to be executed isprocessing of assigning the copy source LU to the host 100 or processingof assigning the copy destination LU in the remote copy or theintra-device replication (step 2100).

If the processing to be executed is judged to be processing of assigningthe copy source LU to the host 100 at the step 2100, then the storagemanagement server 10000 conducts processing of assigning an LU to thehost. Details of the present processing will be described later (step2200). Thereafter, the storage management server 10000 inquires of theuser whether a copy destination LU should be assigned. To be concrete,display for inquiring whether processing should be conducted is outputto the output unit 15000 (step 2300).

If the copy destination LU assignment is ordered by the user at the step2100, or if the copy destination LU assignment is ordered by the user atthe step 2300, then the storage management server 10000 conducts copydestination LU assignment processing. As for the present processing aswell, details will be described later (step 2400). Thereafter, thestorage management server 10000 finishes the LU assignment processing.If the copy destination LU assignment processing is judged at the step2300 to be unnecessary, then the storage management server 10000finishes the LU assignment processing immediately.

FIG. 16 is a flow chart showing a detailed procedure of the processingof assigning an LU to the host executed at the step 2200 shown in FIG.15. The storage management server 10000 receives a condition (hereafterreferred to as parameters) required of the copy source LU, from theuser. In addition to basic information required for LU creation, such asa subject device in which an LU is created, a storage capacity of theLU, a host FC I/F, a SCSI ID, and a LUN, the parameters includeinformation concerning evaluation items registered in the “item” columnof the LU evaluation item table 13400 (step 2210).

Thereafter, the storage management server 10000 conducts assignmentcandidate LU search processing of selecting a suitable LU as a candidateof the copy source LU on the basis of the parameters given by the user.Details of the present processing will be described later (step 2220).Thereafter, the storage management server 10000 exhibits the selected LUcandidate to the user, and requests user's ascertain-ment (step 2230).

If the user has admitted the exhibited LU candidate as the copy sourceLU at the step 2230, then the storage management server 10000 updatesthe LU management table 245 stored in the disk array 701 having theadmitted LU, and its duplication 245′. To be concrete, with respect tothe LU management table 245′ stored in the storage repository 13200, thestorage management server 10000 first alters the “host assignmentsituation” column 245 b for the admitted LU to “present”, and registersvalues of parameters given by the user in the “SCSI ID” column 245 c andthe “LUN” column 245 d. Thereafter, the storage management server 10000orders the disk array 701 having the admitted LU to reflect updatecontents of the LU management table 245′ in the LU management table 245(step 2240).

Thereafter, the storage management server 10000 orders the disk arraycontrol unit 200 to execute the LU management on the basis of the LUmanagement table 245 in which update has been reflected, and finishesthe processing of assigning an LU to the host (step 2250).

If the exhibited LU is rejected by the user at the step 2230, then thestorage management server 10000 discontinues the processing of assigningan LU to the host (step 2260). In order to achieve automatization of theprocessing, processing of setting the selected LU as the copy source LUmay be conducted without exhibiting the selected LU to the user.

FIG. 17 is a flow chart showing a detailed procedure of the copydestination LU assignment processing indicated by the step 2400 in FIG.15.

The storage management server 10000 receives parameters for selectingthe copy destination LU from the user. The parameters are theinformation described above with reference to the copy source LU (step2410).

Thereafter, the storage management server 10000 conducts assignmentcandidate LU search processing for selecting a candidate that can becomethe copy destination LU on the basis of the parameters given by theuser. Details of the present processing will be described later (step2420). Thereafter, the storage management server 10000 exhibits thecandidate of the copy destination LU selected at the step 2420 to theuser, and requests ascertainment of use of the selected LU (step 2430).

If the user admits the exhibited LU as the copy destination LU at thestep 2430, then the storage management server 10000 updates the LU pairmanagement table 246, the LU pair management table 245, and theirduplications 246′ and 245′. Furthermore, the storage management server10000 orders the disk array 701 that stores the selected LU to reflectthe updated contents in respective tables. To be concrete, with respectto the LU pair management table 246′, the storage management server10000 newly creates an LU pair entry for the selected copy destinationLU, and registers parameters specified by the user and information ofthe selected copy destination LU. With respect to the LU managementtable 245′, the storage management server 10000 alters the “hostassignment situation” column 245 b of the selected LU to “present”, andregisters parameter values in the “SCSI ID” column 245 c and the “LUN”column 245 d (step 2440).

Thereafter, the storage management server 10000 orders the disk arraycontrol unit 200 in the disk array 701 having a copy source LU pairedwith the selected copy destination LU to execute remote copy processingor intra-device replication processing on the basis of the pair LUmanagement table 246 obtained after the update, and finishes the copydestination LU assignment processing (step 2450).

If the storage management server 10000 has rejected the exhibited copydestination LU at the step 2430, then it discontinues the copydestination LU assignment processing, and finishes the copy destinationLU assignment processing (step 2460). In order to achieve theautomatization of the processing, processing of setting the selected LUas the copy destination LU may be conducted without exhibiting theselected LU to the user.

FIG. 18 is a flow chart showing a detailed procedure of the assignmentcandidate LU search processing shown in the step 2220 in FIG. 16 and thestep 2420 in FIG. 17.

First, the storage management server 10000 extracts an LU that is notbeing used by the host 100 from the LU management table 245′ stored inthe storage repository 13200. To be concrete, an LU having “present”registered in the “host assignment situation” column 245 b in the LUmanagement table 245′ is judged to have been already used, and a maximumvalue (+99999 in FIG. 9) is registered in the evaluation value. An LUhaving “absent” registered in the “host assignment situation” column 245b is judged to have not been used yet, and the evaluation value is resetto 0 (step 3020).

Subsequently, the storage management server 10000 gives an evaluationvalue to every unused LU extracted at the step 3020, with respect toeach of items registered in the LU evaluation item table 1340. Aconcrete example will be described later (step 3030).

Thereafter, the storage management server 10000 outputs an LU that isminimum in the value of the “evaluation value” column 245 i and that isincluded in all LUs registered in the LU management table 245′ as acandidate for the copy source LU or the copy destination LU (step 3040).

The evaluation values registered in the LU management table 245′ areupdated together when the storage management server 10000 orders eachdisk array 701 to update the LU management table 245 (steps 2240 and2440).

Hereafter, four concrete examples of the step 3030 will be described.

As a first example, evaluation conducted when the user has specified the“kind” as “FC” will now be described. By ascertaining the “evaluationsubject LU management table” column 13400 b, the storage managementserver 10000 ascertains that a column in the LU management table 245′ tobe compared with the user's specification value “FC” is the “LU kind”column. Thereafter, the storage management server 10000 selects one ofextracted unused LUs, and ascertains the content of the “LU kind” columnin the LU management table 245′ that corresponds to the LU. Ifinformation registered in the “LU kind” column is “FC”, then thecondition specified by the user is met, and the storage managementserver 10000 adds 0 to the evaluation value column 245 iin the LUmanagement table 245′ with respect to the unused LU, in accordance witha value that is registered in the “penalty at the time of conditionsatisfaction” column 13400 d and that corresponds to the “kind” item. Ifinformation registered in the “LU kind” column is “ATA”, then thecondition input by the user is not met, and consequently the storagemanagement server 10000 adds +100 to the evaluation value column 245 iin the LU management table 245′ with respect to the unused LU, inaccordance with a value that is registered in the “penalty at the timeof condition unsatisfaction” column 13400 e and that corresponds to the“kind” item.

The storage management server 10000 repeats the processing describedabove, i.e., processing of making a decision as to whether the conditionspecified by the user is met from item to item, and adding apredetermined value to the evaluation value column 245 i in the LUmanagement table 245′ as an evaluation value in accordance with a resultof the decision, until evaluation of all items shown in the LUevaluation item table 13400 has been applied to all extracted unusedLUs. As a result of the present processing, the values of the evaluationvalue column 245 i in the LU management table 245′ for all unused LUsare determined. It is shown in this concrete example that the storagemanagement server 10000 can provide an LU including FC disk devices as acandidate as a result of selection of the kind of the disk device as“FC” conducted by the user.

As a second example, evaluation conducted when the user creates an LUfor backup operation will now be described. In the operation form inwhich the data backup is held over a plurality of generations, it isconceivable to use an LU formed of inexpensive disk devices or an LUformed of disk devices that are hardly usable for ordinary businessoperation because of their short remaining lifetime, as the LU forbackup. For the sake of such a case, an evaluation item “LU operation”as shown in FIG. 14 is defined in the present example. The presentevaluation item is an item for evaluating an LU so that the storagemanagement server 10000 may provide an LU that is “ATA” in “LU kind” and“1000 hours or less” in “LU remaining lifetime” preferentially as acandidate when the user has specified “backup” as “LU operation.” Theevaluation procedure is the same as that in the first example. Owing tothis evaluation item, the storage management server 10000 can exhibit anLU candidate more suitable for backup use to the user.

As a third example, evaluation for effecting LU creation according tothe reliability requested by the user will now be described. In such acase, it is defined that “LU remaining lifetime” is evaluated in anevaluation item “reliability” as shown in FIG. 14. The presentevaluation item is an item for evaluating each LU so that the storagemanagement server 10000 may provide an LU that is “at least 30000 hours”in “LU remaining lifetime” preferentially as a candidate when the userhas specified “high” as “reliability.” Owing to this evaluation item,the storage management server 10000 can evaluate the remaining lifetimeby using a predefined evaluation criterion and provide a suitable LUcandidate.

As a fourth example, evaluation for conducting LU creation according tothe number of copy destinations preset by the user will now bedescribed. In some cases, a large number of copy destinations arecreated by utilizing the function of the remote copy or the intra-devicereplication in order to hold data over a plurality of generations asdescribed with reference to the second example. In such a case, it isdefined that “LU kind” is evaluated in an evaluation item “the number ofcopy destinations” as shown in FIG. 14. The present evaluation item isan item for evaluating each LU so that the storage management server10000 may preferentially search an inexpensive ATA LU and exhibit it tothe user as a candidate when the user has specified a large number ofcopy destinations. Owing to the present evaluation item, the storagemanagement server 10000 can evaluate the LU kind by using a predefinedevaluation criterion, on the basis of the number of copy destinationsspecified by the user, and provide a suitable copy destination LUcandidate.

In the present embodiment, the storage management server 10000implements lifetime management in the LU level in a disk array 701 thatincludes a mixture of disk devices differing in input and output I/Fs.Hereafter, this processing will be referred to as LU lifetime managementprocessing. Unless otherwise stated, each processing is effected byexecution of the storage manager 13100 conducted by the CPU 11000 in thestorage management server 10000.

FIG. 20 is a flow chart showing a procedure of LU remaining lifetimemanagement processing.

The storage management server 10000 periodically monitors the LUremaining lifetime by using information in the LU management tables 245′respectively of the disk arrays 701A and 701B, which is periodicallyupdated by the storage repository 13200. To be concrete, with respect toeach LU specified in the “device ID” column 13500 b and “monitoringsubject LU list” column 13500 c in the LU remaining life watermark table13500, the storage management server 10000 compares a value registeredin the “LU remaining lifetime” column 245 g in the LU management table245′ corresponding to each LU with a watermark preset in each LU (avalue registered in “remaining lifetime watermark” column 13500 dcorresponding to each LU). If a plurality of watermarks can be appliedto one LU according to the situation preset in the “monitoring subjectLU list” column 13500 c, then such a watermark as to maximize the valuein the “remaining lifetime watermark” column 13500 d is applied (step4010).

If as a result of the comparison the remaining lifetime of each LU isless than the value registered in the “remaining lifetime watermark”column 13500 d, then the storage management server 10000 judges that LUto be an LU that needs a warning output (step 4020).

If an LU that becomes a subject of warning does not exist at the step4020, then the storage management server 10000 returns to the processingin the step 4010 and continues the LU remaining lifetime management.

If an LU that becomes a subject of warning exists at the step 4020, thenthe storage management server 10000 discriminates a disk device that isless in remaining lifetime than the watermark, with respect to the LUthat needs the pertinent warning output, and determines whetherautomatic migration has been specified for that disk device. To beconcrete, with respect to all disk devices stated in the “drive No.list” column 245 h in the LU management table 245′ to which the LU thatis less in remaining lifetime than the watermark belongs, the storagemanagement server 10000 examines the “remaining lifetime” column 240 hin the drive management table 240′, discriminates disk devices that areless in remaining lifetime than the watermark, and ascertains the“automatic migration specification” column 249 (step 4030).

If automatic migration is specified in all disk devices included in anLU that is less in remaining lifetime than the watermark at the step4030, then the storage management server 10000 outputs only a warning.If the disk array device does not start the automatic migrationoperation, then the storage management server 10000 orders the diskarray device to conduct automatic migration. As concrete examples of thewarning content, “monitoring time”, “device ID in disk array”, “LU No.”,“drive No. that is less in remaining lifetime than watermark”, and“device ID and LU No. in the related copy source or copy destination LU”can be mentioned.

When outputting the “device ID and LU No. in the related copy source orcopy destination LU”, information in the LU pair management table 246held in the storage repository 13200 is used. By outputting “device IDand LU No. in the related copy source or copy destination LU”, the usercan immediately recognize the possibility that the LU that has becomethe warning subject will affect another copy source or copy destination,and in some cases the user can execute manual alteration of LU paircaused by excess of remaining lifetime (step 4040).

If automatic migration is not specified for even one of disk devicesincluded in an LU that is less in remaining lifetime than the watermarkat the step 4030, then the storage management server 10000 outputs awarning to the user, and outputs a message for urging the migrationspecification or the drive exchange order. As concrete examples of thewarning content, “drive Nos. which become candidates of migrationdestination” can be mentioned, besides the contents stated in the step4040.

In determining “drive Nos. which become candidates of migrationdestination”, the storage management server 10000 determines that unuseddisk devices that are the same in drive kind and that are not preset inarray configuration should be searched by using the information in thedrive management table 240′ held in the storage repository 13200. Byusing the output of “drive Nos. which become candidates of migrationdestination”, the user can reduce the burden of searching for anautomatic migration destination for conducting migration specification.Since the disk array automatically determines the automatic migrationdestination of the disk device, the output of the “drive Nos. whichbecome candidates of migration destination” may be omitted (step 4050).

According to the present embodiment, when creating LUs of a disk arrayincluding a mixture of disk drives differing in input and output l/Fsand reliability, LUs can be created while considering the performanceand reliability of the disk drive, on the basis of characteristicsordered by the user. Furthermore, in the case where the disk array has afunction of the remote copy or intra-device replication, the copydestination LU can also be automatically determined while consideringthe performance and reliability of the disk drive, on the basis ofcharacteristics ordered by the user. In addition, lifetime management ofdisk devices in a disk array, which is hard for the user to be consciousof, can be conducted in the level of LU, which is a logical volume.

Even if the disk array 700 has the configuration of the secondembodiment, the storage management server 10000 in the presentembodiment can conduct the LU creation and the lifetime management inthe LU level while considering the performance and reliability of a diskdevice.

The lifetime management conducted by the storage management server 10000while taking an LU as the unit in the present embodiment may be executedby the control unit 200 in the disk array 700 in the first embodiment.In this case, the parameters in the lifetime management conducted in thefirst embodiment while taking a disk device as the unit should bealtered to LU remaining lifetime. If an LU that is less in LU remaininglife than some watermark is found, disk devices included in the LUshould be detected and processing of determining whether automaticmigration is present should be conducted for each of the disk devices.

According to the present invention, it becomes possible to provide amixture of disk devices differing in, for example, lifetime andremaining lifetime, and manage them in the same disk array. Furthermore,it is possible to determine the user's use of a volume while consideringthe reliability of the disk devices included in the array. Furthermore,it is possible to determine the user's use of a volume while consideringthe performance of the disk devices included in the array. Furthermore,it becomes possible to provide a mixture of disk devices differing incontrol scheme, and manage them in the same disk array.

Furthermore, there is an effect that an ATA disk device can be connectedto a fibre channel arbitrated loop, which is an interface for connectinga fibre channel disk device.

In addition, it becomes possible to provide automatic creation of LUsand lifetime management in the LU level with due regard to theperformance and reliability of disk devices, and reduce the user'sburden of management in the storage system.

It should be further understood by those skilled in the art thatalthough the foregoing description has been made on embodiments of theinvention, the invention is not limited thereto and various changes andmodifications may be made without departing from the spirit of theinvention and the scope of the appended claims.

1. A storage system comprising: at least one first type of disk deviceseach including an FC interface; a controller coupled to said at leastone first type of disk devices; and at least one second type of diskdevices each includidge an ATA interface, wherein copy data of datastored in said at least one first type of disk devices is stored in saidat least one second type of disk devices.
 2. A storage system accordingto claim 1, wherein said at least one second type of disk devices iscoupled to said controller, and said controller is configured to storecopy data of data stored in said at least one first type of disk devicesin said at least one second type of disk devices.
 3. A storage systemaccording to claim 2, wherein said at least one second type of diskdevices configures a second type of RAID group different from a firsttype of RAID group configured with said at least one first type of diskdevices.
 4. A storage system according to claim 3, wherein said secondtype of RAID group and said first type of RAID group are both in a RAID5 configuration.
 5. A storage system according to claim 3, wherein copydata of data stored in a first type of logical storage area, which isconfigured in said first type of RAID group, is stored in a second typeof logical storage area configured in said second type of RAID group. 6.A storage system according to claim 5, wherein said controller isconfigured to take a snapshot of data stored in said first type oflogical storage area, by changing a state of a pair between said firsttype of logical storage area and said second type of logical storagearea from pair state to split state, and keep data stored in said secondtype of logical storage area as backup data of data stored in said firsttype of logical storage area.
 7. A storage system according to claim 5,wherein said controller is configured to take a snapshot of data storedin said first type of logical storage area, by changing a state of apair between said first type of logical storage area and said secondtype of logical storage area from pair state to split state, and aftertaking the snapshot, data stored in said second type of logical storagearea is written into a tape device to keep backup data of data stored insaid first type of logical storage area in said tape device.
 8. Astorage system according to claim 2, wherein copy data of data stored insaid at least one first type of disk devices is further stored in a tapedevice as a backup by writing data stored in said at least one secondtype of disk devices into said tape device.
 9. A storage systemaccording to claim 2, wherein said controller includes an FC interface,to which said at least one first type of disk devices and said at leastone second type of disk devices are coupled.
 10. A storage systemaccording to claim 9, wherein said at least one first type of diskdevices and said at least one second type of disk devices are coupled tosaid FC interface via an FC loop.
 11. A storage system according toclaim 9, wherein said at least one second type of disk devices arecoupled to said FC interface via an FC-ATA conversion interface.
 12. Adata backup system comprising: a source storage system including atleast one first type of disk devices each comprising an FC interface anda source controller coupled to said at least one first type of diskdevices; and a destination storage system including at least one secondtype of disk devices each comprising an ATA interface and a destinationcontroller coupled to said at least one second type of disk devices,wherein said source controller is configured to send replicated data ofdata stored in said at least one first type of disk devices to saiddestination storage system to store said replicated data into said atleast one second type of disk devices.
 13. A data backup systemaccording to claim 12, wherein said at least one first type of diskdevices configures a first type RAID group, and said at least one secondtype of disk devices configures a second type RAID group.
 14. A databackup system according to claim 13, wherein both of said first type ofRAID group and said second type of RAID group are in a RAID 5configuration.
 15. A data backup system according to claim 13, whereinsaid source controller is configured to store replicated data of datastored in a first type of logical storage area configured in said firsttype of RAID group into a second type of logical storage area configuredin said second type of RAID group.
 16. A data backup system according toclaim 15, wherein said at least one second type of disk devicesconfigures at least one second type of RAID groups, and plural secondtype of logical storage areas are configured in said at least one secondtype of RAID groups, said source controller is configured to storereplicated data of data stored in said first type of logical storagearea into one of said plural second type of logical storage areas, saiddestination controller is configured to take a snapshot of data storedin said one of said plural second type of logical storage areas, bychanging a state of a pair between said one of said plural second typeof logical storage areas and another one of said plural second type oflogical storage areas, from pair state to split state, and keep datastored in said another one of said plural second type of logical storagearea as backup data of data stored in said first type of logical storagearea.
 17. A data backup system according to claim 15, wherein said atleast one second type of disk devices configures at least one secondtype of RAID groups, and plural second type of logical storage areas areconfigured in said at least one second type of RAID groups, said sourcecontroller is configured to store said replicated data of data stored insaid first type of logical storage area into one of said plural secondtype of logical storage areas in said destination storage system, saiddestination controller is configured to take a snapshot of data storedin said one of said plural second type of logical storage areas, bychanging a pair state of a pair between said one of said plural secondtype of logical storage areas and another one of said plural second typeof logical storage areas, from pair state to split state, and aftertaking the snapshot, data stored in said another one of said pluralsecond type of logical storage areas are written into a tape device tokeep a backup of data stored in said first type of logical storage areain said tape device.
 18. A data backup system according to claim 12,wherein said replicated data is further stored in a tape device asbackup data by writing data stored in said at least one second type ofdisk devices into said tape device.
 19. A data backup system comprising:a source storage system including at least one first type of diskdevices each having a PC interface and a source controller coupled tosaid at least one first type of disk devices; and a destination storagesystem including at least one first type of disk devices each having anFC interface, at least one second type of disk devices each having anATA interface, and a destination controller coupled to said at least onefirst type of disk devices, said at least one second type of diskdevices, and said source controller, wherein said at least one firsttype of disk devices in said source storage system configures a sourcefirst type of RAID group, in which a source first type of logicalstorage area is configured, said at least one first type of disk devicesin said destination storage system configures a destination first typeof RAID group, in which a destination first type of logical storage areais configured, and said at least one second type disk deices in saiddestination storage system configures an second type of RAID group, inwhich a second type of logical storage area is configured, and whereinsaid source controller is configured to store replicated data of datastored in said source first type of logical storage area into saiddestination first type of logical storage area, and said destinationcontroller is configured to take a snapshot of data stored in saiddestination first type of logical storage area by changing a pair stateof a pair between said destination first type of logical storage areaand said second type of logical storage area from pair state to splitstate.
 20. A data backup system according to claim 19, wherein saiddestination controller is configured to keep data stored in said secondtype of logical storage area as backup data of data stored in saidsource first type of logical storage area.
 21. A data backup systemaccording to claim 19, wherein data stored in said second type oflogical storage area is written into a tape device to keep backup dataof data stored in said source first type of logical storage area in saidtape device.